The navy lieutenant captain Peter Orlov and Ivan Myraviev have been serving in the Slav submarine for quite a time. Young and mischievous against time, they used to be best friends. In 1986 they both were assigned to Sevastopol for future service. There they met a pretty girl and fell in love with her at first sight. Nelly chose Ivan and their great friendship cracked. Later on, in the early 90s, after the Soviet Fleet division, the Slav crew refused allegiance to the Ukraine and was assigned to Severogorsk. The crew is preparing for a regular military exercise. The commander, Captain 1st Rank Gennady Yanychar announces the assigned mission. The submarine is to torpedo the maneuver enemy, then leave the area and make itself undetectable with any device at all for a certain time. Nobody in the Exercise Center knows where the submarine might go. And nobody knows it is facing a catastrophe.